类型不匹配：‘IsNumric‘是怎么回事？

<%
   '验证是否为int型
   Function IsInteger(Val)
      On Error Resume Next
      IF VarType(CInt(Val))<>2 Then
         IsInteger=False
      Else
         IsInteger=True
      End IF
   End Function
   ParentID=GetRs("Select ParentID From ArticleClass where ClassID="&ClassID)   
   If IsInteger(ParentID) Then
      ParentID=int(ParentID)
      TmpSql="Select ClassID,ClassName From ArticleClass where ClassID="&ParentID
   Else        
      ParentID=0         
      TmpSql="Select ClassID,ClassName From ArticleClass where ParentID="&ClassID   
   End If
   'Response.write tmpsql
   Call OpenCreateRs(TmpConn,TmpRs,TmpSql)
   Do While Not TmpRs.EOF            
%>